Retention of Halyomorpha halys (Hemiptera:Pentatomidae) adults and nymphs on wild and cultivated host trees as a proxy for host acceptability at different points in the growing season

Halyomorpha halys (Hemiptera:Pentatomidae) is an invasive, polyphagous herbivore that has spread across much of the United States and is a major tree fruit pest in the Mid-Atlantic region. Many Mid-Atlantic orchards are bordered by woodlands containing its wild hosts. The species composition and their relative abundance in these woodlands may influence H. halys density and pest pressure. To examine the acceptability of some of these hosts based on H. halys retention time, a study was conducted using harmonic radar technology. Wild hosts (black locust, tree of heaven, mulberry, hackberry), cultivated hosts (peach, apple, and apple baited with H. halys pheromone lures), and a non-host (1 m² plot of cut grass) were used. Field-collected H. halys adults and nymphs were placed in the mid-canopy of potted tree hosts ~1.5 m tall and center of the grass plot, and their presence/absence was recorded using harmonic radar and visual checks at 1, 2, 4, 8, and 24+ hour intervals post-release. Studies were conducted during early, mid, and late season, 2020, with 8, 9, and 10 adults per treatment, respectively, and 9 nymphs per treatment during the mid-season only. Results were analyzed by life stage and season using a one-way ANOVA followed by Dunnett’s Test. Results will be discussed in relation to the retention time on the non-host, grass, versus host species, and the influence of hosts on H. halys behavior seasonally. These results will ultimately contribute to the overall understanding of H. halys host use patterns throughout the growing season.